group velocity

常见例句

When the medium density increases (with more atoms), the slow group velocity decreases.
当介质的密度增加时（包含更多的原子），群速度就降低。
In light of this finding, scientists have wondered whether single photons travel at the group velocity or the signal velocity.
在这些发现的基础上，科学家曾经怀疑，是否单个光子可以达到“群速度”和“信号传播速度”。
The main wave packet of a single photon travels no faster than c in any medium, and can be delayed up to 500 ns in a slow light medium where the group velocity is slower than c.
单个光子的波包的传递速度在介质中不比光速快，而且可以在慢光介质中延迟到500纳秒。慢光介质中的群速度比光速慢。

The number of passengers in the U.S. paying for first-class, business-class and full-price economy airfares has halved in the past five years, from 18% to 9%, says the Velocity Group, an aviation consultancy.
FORBES: Magazine Article
One of his recommendations is Jonathan Miller, a former chief executive at AOL who is now a partner at Velocity Interactive Group, a Los Angeles-based firm that invests in digital media properties.
FORBES: Magazine Article